The Kyriad voucher code above returns a 10€ from the flexible rate, meaning that you can always change / cancel your reservation if plans change.

In the search form on the homepage, push the + button below the information the number of guests. You will then see several fields, among which the one called "Promo code". Paste there the Kyriad.com discount code KYTDFR201301 and then push the "Search" button (see print-screen below):

Then, in the results page showing the room types and rates, you will see the special discounted rate marked with a green label, called "Promo Code" - see print screen below:

Just select that rate and continue with the booking process, as usual.